Ceiling panel

ABSTRACT

The invention relates to a metal ceiling panel having flange portions with complementary engagement areas formed such that two juxtaposed panels can be interconnected in a tight manner. The shape of the flange portions corresponds to the contour of an inclined S whereby the joint between two such panels becomes even tighter in the event of a substantial increase of the temperature in the space below the ceiling panel. The shape of the flange portions also brigs about an increased stability of an underside covering for a ceiling formed by a plurality of such panels when exposed to a fire.

[0001] The present invention relates to a ceiling panel of the type defined in the introductory portion of claim 1.

[0002] U.S. Pat. Nos 3,462,906 and 4,223,503 as well as British Patent No 1249765, among others, disclose examples of such ceiling panels, which are mounted side by side, and which form an underside covering for a ceiling over a room in the interconnected state. The individual panels are made of a metal material which has been machined by bending or rolling. The underside covering is typically supported by a supporting structure in the form of a system of supporting strips, which are arranged on the walls defining the room. The underside covering may moreover be adapted to carry a suitable thermal and/or acoustic insulation, e.g. in the form of insulation batts which are placed on the surface of the panels facing the ceiling.

[0003] A common property of the known ceiling panels underlying the invention is that they are self-supporting and that they may be interconnected via complementary and elastically deformable engagement areas arranged along the longitudinal edge sides of the panels. When the panels are self-supporting and interconnected, the own weight of each panel can also be transferred partly to the supporting structure via the adjoining panels. As the engagement areas extend in the full length of the longitudinal edge sides of the panels, it is moreover possible to ensure a desired tightness of the underside covering against flame penetration and passage of smoke or other gases, which may e.g. be emitted from burning objects in the room below the underside covering. In the known underside coverings, however, it is frequently difficult to remove one or more of the ceiling panels, when so required, without damaging the adjoining ceiling panels, or without having to loosen screws or similar fasteners. Such removal of some of the ceiling panels may be desired e.g. to obtain access to installations in the space between the ceiling and the underside covering.

[0004] In the construction of ceiling panels allowance must of course be made for the static impacts on the panels because of e.g. the own weight and because of the weight of overlying insulation batts, if any, which might necessitate reinforcement of the panels with ribs or the like. Furthermore, allowance must be made for the special conditions that may occur in connection with a fire in the room below the underside covering. In addition to the fact that the panels must constructively be arranged to prevent penetration of flames and smoke in the engagement areas, as mentioned, they must also be constructed such that the stability and integrity of the underside covering can be maintained at elevated temperatures for a given period of time. It will be appreciated that the fire load thereby also make demands on the strength of the locking engagement between the flange portions, as this locking engagement must not only ensure the continued tightness, but must also ensure that forces because of own weight and insulation material, if any, can still be transferred from one ceiling panel to the next one and further to the supporting structure which supports the underside covering.

[0005] With the previously known underside coverings, however, it has been difficult to satisfy modern legislative requirements as regards the time during which the underside covering is tight.

[0006] The object of the present invention is to provide an improved ceiling panel which inter alia provides concurrent favourable properties as regards all the below-mentioned aspects:

[0007] the engagement areas allow transfer of forces from one ceiling panel to the next one

[0008] the joint between the panels is extremely tight in normal use

[0009] a panel may be removed and mounted again without also having to remove one or more of the other panels

[0010] the load-bearing capacity and integrity of the underside covering may be maintained for a relatively long time at high temperatures

[0011] the tightness of the covering may be maintained for a relatively long time at high temperatures.

[0012] This is achieved according to the invention as defined in the characterizing portion of claim 1.

[0013] When the first and second flange portions exhibit a respective inclined first part, it has surprisingly been found that the above specifications may be observed. In a fire, the entire flange portion will thus try to turn down toward the web portion of the ceiling panels. This provides a very reliable tightness of the joint, as at least the complementary engagement areas adjoining the web portion will be kept in intimate mutual contact. Moreover, according to the invention, it is still possible, in the normal state, to release a single panel from the other panels by affecting the panel concerned by an upwardly directed pressure impact that releases the locking engagement, e.g. to generate an elastic deformation of the flange portions whereby the locking engagement at one longitudinal side edge may be released.

[0014] When, as stated in claim 2, the one flange portion is formed with a locking section having a free edge extending along the edge side at a maximum distance from the web portion of the panel, improved interlocking of two adjoining ceiling panels is achieved, as the stability of the locking section when subjected to the impact of a fire will tend to fail, i.e. the locking section will tend to deform by buckling because of the occurring compressive stresses which will be maximum in this area of the panel most remote from the web portion. It has been found by tests that this folding combined with the above-mentioned downward turning of the entire flange portion generates a greater resistance to disengagement of the adjoining ceiling panel from the locking engagement in a fire, relative to the normal state, which manifests itself in the fact that the integrity of the covering is maintained for a relatively longer time.

[0015] When the ceiling panel is constructed with the angular relationships defined in the claims, it has been found by tests that particularly favourable conditions are achieved, as the angles defined in claim 3 also facilitate assembly and disassembly of panels to a certain extent, and as the relationship defined in claim 9 gives the underside covering additional advantages in terms of sealing. Also, the preferred embodiments provide a reduction in the vibration-caused noise, which frequently occurs when ceiling panels of the present general type are used onboard ships.

[0016] The invention also relates to an underside covering produced by assembling a plurality of ceiling panels according to the invention.

[0017] A preferred embodiment of the invention is shown in the drawing, in which

[0018]FIG. 1 shows a cross-section through a panel,

[0019]FIG. 2 shows two panels according to the invention which are connected in the engagement area, and

[0020]FIG. 3 illustrates the development in a fire where the joint is deformed,

[0021]FIG. 4 shows the locking section in a deformed state in a fire, and

[0022]FIG. 5 shows an expedient edge panel for the mounting of the ceiling panels according to the invention.

[0023]FIG. 1 shows a cross-section through a ceiling panel 1 according to the invention. The ceiling panel 1 has a web portion 5 with an upper side which, in the mounted state of the ceiling panel, faces an overlying ceiling, and a lower side which is intended to face an underlying room. The web portion 5, which forms the visible part of the ceiling panel in the room, is preferably plane, but may optionally be provided with a modest curvature. However, it will be appreciated that the web portion 5 defines an imaginary main extent plane for the ceiling panel, viz. a plane which is substantially parallel with the ceiling.

[0024] The ceiling panel 1 preferably has a rectangular basic form with a longitudinal central area M, and the web portion 5 has longitudinal edge sides 8, 9 and transverse edge sides. Flange portions 20, 40 are arranged along each of the longitudinal edge sides 8, 9 and extend in the entire length of the panel 1. The shown ceiling panel is preferably made from a flat metallic plate workpiece, and the flange portions 20, 40 are provided by bending or similar working.

[0025] The flange portions 20, 40 comprise complementary engagement areas by means of which two adjoining identical ceiling panels 1 may be interconnected. The engagement areas are generally designated by the reference numerals 21 and 41 in FIG. 1 and thus comprise respective panel parts which extend longitudinally of the ceiling panel 1 in various mutual angles.

[0026] More particularly, the engagement areas 21, 41 are each formed approximately with the shape of an S which is inclined relative to a longitudinal plane H. The plane H extends perpendicularly to the main extent plane of the ceiling panel 1, and the angles defined below are calculated as measured relative to a plane perpendicular to the main extent plane in parallel with the plane H. As shown, the engagement area 41 consists of a first part 42 which extends upwards and away from the web portion 5 at an angle α of preferably about 12° relative to the plane H. The part 42 merges via a bend into a second part 44 which extends downwards back in the direction toward the web portion 5 at an angle θ of preferably about 125°, and which, via a bend or constriction 45, merges into a third part 46, which extends upwards away from the central area M at an angle β of likewise about 12°. Via a further bend the third part 46 merges into a fourth part 48 which forms an angle φ of preferably about 79° relative to the plane H. Before the fourth part 48 reaches an imaginary extension of the part 42, the fourth part 48, via a bend, merges into a fifth part 50, which extends upwards away from the web portion 5 at an angle γ of about 12°. It will thus be appreciated that the first, third and fifth parts extend substantially mutually in parallel with approximately the same inclination relative to the plane H, which results in well-controlled deformations in a fire. The fifth part 50 will be called the “locking section” below.

[0027] It applies to the engagement area 21 that this is likewise composed of a first part 22 which merges into a second part 24, which in turn merges into a third part 26 with an end portion 28 to form a nose 25, and that the overall course of these parts approximately corresponds to the course of the corresponding parts of the engagement area 41. However, it will preferably be so that the angles of the parts relative to the plane H are selected such that the angle x is greater than the angle x', and that the angle y' is greater than the angle y, thereby providing a clamping force upon assembly of two ceiling panels when the nose 25 is inserted into the constriction 45. The mentioned end portion may optionally be formed as a bend which merges into a rearwardly directed extension 29 which imparts a certain rigidity to the part 26. It will be appreciated from FIG. 1 that angles α, β and θ corresponding to the angles α, β and θ in the engagement area 41 may be provided in the engagement area 21 as well.

[0028]FIG. 2 shows two identical ceiling panels 1, 1′ arranged side by side and assembled by the insertion of the engagement area 21′ into the engagement area 41, i.e. by the insertion of the nose 25 into the constriction 45. As mentioned, the engagement areas 21 and 41 are preferably, but not necessarily shaped such that this insertion establishes a clamping of the engagement area 21′, one of the engagement areas being deformed elastically during the insertion. As will appear, the insertion areas are moreover shaped so as to provide suspension of the ceiling panel 1′ from the ceiling panel 1, thereby allowing vertical forces from e.g. the own weight of the panels to be transferred across the joint.

[0029] In the use of the ceiling panel for covering a ceiling a plurality of the ceiling panels 1 are mounted side by side at a desired distance below the ceiling, as shown in FIG. 2. Before the mounting, a supporting structure in the form of e.g. supporting strips secured to the walls is arranged at a suitable height. The supporting structure is adapted to support and retain the transverse edge sides of the ceiling panels 1, as each ceiling panel thus extends as a self-supporting unit between two supporting strips, as well as preferably also the longitudinal edge sides of the outermost ceiling panels of the underside covering. For use as an underside covering in e.g. cabins on board ships, the ceiling panels will typically have a length of about 3 meters, corresponding to the distance between two of the walls of the cabin, a width of about 0.3 meter and a height of the engagement area 21 of about 23 mm and of the engagement area 41 of about 25 mm. The ceiling panels are mounted singly side by side, with the nose 25 of a new ceiling panel being inserted into the constriction 45. It will moreover be seen from FIG. 2 that the individual ceiling panels may easily be disassembled from each other by applying an upwardly directed pressure along the left edge side 8 of the ceiling panel, thereby pressing the end portion 28 clear of the part 48 so that the nose 25 may be moved out of the constriction 45. By turning the ceiling panel it may then be moved clear of the adjoining ceiling panels and be removed.

[0030] In order to comply with the present and expected future regulations as regards restriction of the damage caused by a fire, it is necessary to construct the underside covering so that it is tight and thereby prevents passage of flames and smoke from the underlying room, and so that collapse of the ceiling panels is prevented for as long a time as possible at the elevated temperatures in the room. It has been found by fire tests that the present invention provides an extension of the time it takes before there is a real risk of collapse of the underside covering.

[0031] When an underside covering composed of a plurality of self-supporting ceiling panels according to the invention suspended as described above is affected by a fire, the underside covering will typically assume a shape as a single-or double-curved face because of the linear expansion of the material. FIG. 3 shows somewhat exaggerated and schematically how the flange portion 40, as well as the flange portion 20 (not shown) with which the flange portion 40 is connected, is deformed in the course of a fire, and it will be seen how the inclination of the flange portions and the special S-shape of the engagement areas give rise to a downwardly directed turning of the entire joint during a fire load, and that this inclination increases gradually. It will be appreciated that during this deformation a stronger clamping force is simultaneously generated in the joint, which thereby becomes more tight. During this deformation stability failure typically occurs in the part of the cross-section of the ceiling panel in which the greatest compressive stresses occur, i.e. particularly in the locking section 50, which will consequently try to assume a bulging shape with regular creases in the longitudinal direction of the ceiling profile, as shown in FIG. 4. It has been found that this deformation provides an increased resistance to a release of the engagement between the flange portions 20 and 40 and thereby against separation of the joint.

[0032] The stated structure of the flange portions, for one thing, provides an increased resistance against separation forces in the joint between the panels in a fire and thereby against loss of integrity of the covering and thereby collapse of the covering, and, for another, an increased risk of the required tightness against flames and flue gases being lost.

[0033]FIG. 5 shows an edge panel for use in connection with the mounting of ceiling panels according to the invention to form the underside covering. The edge profile is preferably shaped as a half-ceiling panel according to the invention, as the edge profile just comprises one S for connecting the edge profile with the adjoining ceiling panel, it being possible for the opposite longitudinal edge of the edge panel to be provided with a bend so that the longitudinal edge may be connected in a particularly expedient manner with the locking strip which extends from the supporting structure. 

1. A ceiling panel (1) of metal intended to form an underside covering for a ceiling upon assembly with a plurality of corresponding ceiling panels, said ceiling panel comprising: a web portion (5) which defines a main extent plane for the ceiling panel (1), and which is adapted to face the underlying room in the mounted state of the ceiling panel, said web portion (5) having a first longitudinal edge side (9), a second longitudinal edge side (8) and transverse edge sides, a first longitudinal flange portion (40) connected with the web portion (5) at the first longitudinal edge side (9), a second longitudinal flange portion (20) connected with the web portion (5) at the second longitudinal edge side (8), said flange portions (20, 40) comprising complementary engagement areas (21, 41) adapted to generate a releasable locking engagement between the flange portions (20, 40) on two juxtaposed ceiling panels (1), characterized in that the first longitudinal flange portion (40) exhibits: a first part (42), which extends upwards and outwards away from the central area of the web portion (5) at an acute angle α relative to a normal to the main extent plane, and which merges into a second part (44), which extends downwards back in a direction toward the central area of the web portion (5) at an angle θ relative to a normal to the main extent plane, and which merges into a third part (46), which extends upwards and outwards away from the central area of the web portion (5) at an acute angle β relative to a normal to the main extent plane, and which merges into a fourth part (48), which extends upwards and outwards away from the central area of the web portion (5) at an angle φ relative to a normal to the main extent plane, and that the second flange portion (20) exhibits: a first part (22), which extends upwards and inwards toward the central area of the web portion (5) at an acute angle of about α relative to a normal to the main extent plane, and which merges into a second part (24), which extends downwards in a direction away from the central area of the web portion (5) at an angle of about θ relative to a normal to the main extent plane, and which merges into third part (26), which extends upwards and inwards toward the central area of the web portion (5) at an acute angle of about β relative to a normal to the main extent plane.
 2. A ceiling panel according to claim 1, characterized in that the first flange portion (40) comprises a longitudinal locking section (50), which extends from the engagement area (41) upwards and outwards away from the central area of the web portion (5) at an acute angle γ relative to a normal to the main extent plane, and which has a free edge arranged at the greatest distance from the web portion (5) relative to the rest of the flange portion (40), whereby the longitudinal locking section (50) by folding deformation provides an obstacle to the release of said locking engagement.
 3. A ceiling panel according to claim 1 or 2, characterized in that it applies to the first longitudinal flange portion (40): that the angle α is between 5° and 30°, preferably between 10° and 15°, that the angle θ is between about 110° and 130°, that the angle β is between 5° and 30°, preferably between 10° and 15°, that the angle φ is between 55° and 85°, preferably between 65° and 80°.
 4. A ceiling panel according to one of the preceding claims, characterized in that said third part (26) of the second flange portion (20) merges into a fourth part (29), which, via a bend (28), extends downwards approximately in parallel with said third part (26) on the side thereof facing the web portion (5).
 5. A ceiling panel according to one of the preceding claims, characterized in that the releasable engagement is produced by cooperation between the fourth part (48) of the first flange portion (40) and the third part (26) of the second flange portion (20).
 6. A ceiling panel according to any one of the preceding claims, characterized in that the web portion (5) and the first (40) and the second (20) flange portions are formed in one piece by bending of a plate.
 7. A ceiling panel according to any one of the preceding claims, characterized in that the locking engagement is provided by elastic deformation of at least one of the flange portions (20, 40).
 8. A ceiling panel according to any one of the preceding claims, characterized in that it applies to the second flange portion (20) that the angles α, β and θ differ from the corresponding angles of the first flange portion (40) by ±2°.
 9. A ceiling panel according to the preceding claim, characterized in that the angle (x) between the first part (42) and the second part (44) of the first flange portion (40) is greater than the angle (x′) between the first part (22) and the second part (24) of the second flange portion (20), and that the angle (y) between the second part (44) and the third part (46) of the first flange portion (40) is smaller than the angle (y') between the second part (24) and the third part (26) of the second flange portion (20) to provide a clamping force in the assembly of two ceiling panels (1).
 10. A ceiling panel according to any one of the preceding claims 1-7, characterized in that it applies to the second flange portion (20) that the angles α, β and θ are equal to the corresponding angles of the first flange portion (40).
 11. A ceiling panel according to any one of the preceding claims, characterized in that the angle α is equal to the angle β.
 12. An underside covering produced by assembling a plurality of ceiling panels according to claims 1-11 arranged side by side. 